Had this happen multiple times, from my experience it is the magneto, that is the only part I think would do it. You can buy both the magneto and cdi together for about 15$ as you showed on the link for Amazon. I would buy it but replace only the mag first to see it the was the problem, then try with no coil and see what happens. Just try and find what's wrong so you know what to do next time instead of replacing everything and not knowing what actually caused it. Also make sure you keep it dry, one time in my early days I ran my bike through a rainstorm and I left it uncovered outside. I didn't know that the area for the mag was filled with water and it fried the mag.so watch out for water.
